1. Field of the Invention
The present invention relates to a semiconductor device of chip-on-chip structure in which semiconductor chips are bonded to each other in a stacked relation, and to a semiconductor chip for use in such a semiconductor device.
2. Description of Related Art
Semiconductor devices of chip-on-chip structure have been proposed, in which a pair of semiconductor chips are disposed in an opposed relation and electrically connected to each other via bumps. However, the semiconductor devices have many problems to be solved for practical applications.
The chip-on-chip structure is expected to reduce the areas of wiring boards to be incorporated in various electronic systems for size reduction of these systems, as compared with a case where the chips are individually packaged in single-chip packages. For electronic systems such as mobile phones which handle high frequency signals, however, it is important to take protective measures against noises, so that a shielding member should additionally be provided for shielding the entire wiring board. Therefore, it is impossible to achieve drastic size reduction of the systems simply by employing the chip-on-chip structure.